Although the vernal equinox (March 21 this year) is the official start of spring, it seems that it’s the flowers that let us know when spring really begins.
Flowering is quite dependent on the weather, so the timing of blooms varies from year to year. But regardless of the weather, the sequence in which plants bloom should remain about the same.
Some bulbs may show their stuff long before spring is officially proclaimed. Winter aconite (Eranthis) and snowdrops (Galanthus) often pop up during the brief warm-ups in winter, and it’s not unusual for them to have a drift of snow as their background. But this year, the heavy snow blanket likely kept these species in hibernation a bit longer than usual.
Some species of Crocus tend to be right on the money, blooming right about the third week of March, but it will be hard to predict their timing this year. Bulbous Iris (reticulate group) and some species of squill (Scilla) follow along toward the end of the month. Next come daffodils (Narcissus) and spring beauties (Claytonia). As spring progresses, more daffodils, grape hyacinth (Muscari) and early tulips will grace our gardens.
Local weather conditions and microclimates can affect the timing of bloom. Southern areas of the Midwest can be 3-4 weeks ahead of northern areas. Urban areas tend to be warmer than rural areas, and even certain areas of a garden can be warmer than others. Flowers that are planted close to buildings and those in sunny spots tend to bloom before those that are out in the yard or in shady areas.
Bulbous plants have a distinct advantage over some other types of plants due to the large amount of food reserves stored in the bulbs. These plants usually have enough reserves to see them through the spring blooming season. But, if you want to keep these bulbs healthy and productive in the years to come, you may have to give them some help.
In many cases, the bulb’s foliage is not much to look at once the flowers have faded. However, it is absolutely essential that the foliage be allowed to grow so it can manufacture the food reserves, which are then transferred to the bulb for storage. The leaves should be removed only after they’ve begun to yellow and wither on their own. Bulbs can be planted among ground cover plants or intermingled with other perennial flowers to focus attention away from the bulb’s foliage. Spent flowers should be removed to prevent the production of seed, which uses up considerable food reserves from the bulb.
A light side dressing of nitrogen fertilizer helps keep the foliage thriving. Apply a nitrogen-containing product such as ammonium nitrate, bone meal or composted manure according to label directions. The fertilizer should be placed alongside the plants, not directly on the foliage.